Methods and apparatus to monitor components of an aircraft landing system

ABSTRACT

Methods and Apparatus to monitor components of an aircraft landing system are disclosed herein. An example method includes determining an initial temperature of at least one of a wheel or a fuse plug based on a temperature value to be provided by a first temperature sensor; estimating a temperature of a brake assembly based on a temperature value provided by a second temperature sensor; after determining the initial temperature, estimating a subsequent temperature of the at least one of the wheel or the fuse plug; and determining if the subsequent temperature is a peak temperature.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent arises as a continuation application of U.S. patentapplication Ser. No. 13/830,109, filed on Mar. 14, 2013, entitledMethods and Apparatus to Monitor Components of an Aircraft LandingSystem, which is hereby incorporated herein by reference in itsentirety.

FIELD

The present disclosure relates generally to aircraft landing systemsand, more particularly, to methods and apparatus to monitor componentsof an aircraft landing system.

BACKGROUND

Generally, an aircraft includes wheels and brakes to facilitate taxiing,landing, parking, etc. When the brakes are operated, the brakes generateheat. The heat from the brakes may be transferred to the wheels.Generally, each of the wheels includes one or more fuse plugs. A fuseplug may include a seal, which melts upon reaching a thresholdtemperature to release air from a tire on the wheel. Conventionalsystems utilize only brake temperature measurements, which may notcorrelate to wheel temperatures in most instances due to heat shielding.These conventional systems also do not address a concern among operatorsof triggering wheel fuse plugs due to exceeding predeterminedtemperature thresholds of a wheel. As a result, an operator may subjectthemselves to overly conservative delay periods to compensate forinsufficient data regarding actual wheel temperature. It would thereforebe beneficial to provide an enhanced measurement of an existing wheeltemperature and predict a future wheel temperature given a particulardelay period and eventual landing.

SUMMARY

An example apparatus includes apparatus includes a temperaturemonitoring unit to be communicatively coupled to a first temperaturesensor of at least one of a wheel or a fuse plug coupled to the wheeland a second temperature sensor of a brake assembly operatively coupledto the wheel. The temperature monitoring unit includes an initialtemperature determiner to determine an initial temperature of at leastone of the wheel or the fuse plug based on a temperature value to beprovided by the first temperature sensor, a brake energy estimator toestimate a temperature of the brake assembly based on a temperaturevalue provided by the second temperature sensor; a subsequenttemperature estimator to estimate a subsequent temperature of at leastone of the wheel or the fuse plug, the subsequent temperature to bedetermined after the determination of the initial temperature; and apeak temperature estimator to determine if the subsequent temperature isa peak temperature of the at least one of the wheel or the fuse plug.

An example method includes determining an initial temperature of atleast one of a wheel or a fuse plug based on a temperature value to beprovided by a first temperature sensor; estimating a temperature of abrake assembly based on a temperature value provided by a secondtemperature sensor; after determining the initial temperature,estimating a subsequent temperature of the at least one of the wheel orthe fuse plug; and determining if the subsequent temperature is a peaktemperature.

The features, functions and advantages that have been discussed can beachieved independently in various examples or may be combined in yetother examples further details of which can be seen with reference tothe following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example aircraft that may be used to implementexample methods and apparatus disclosed herein.

FIG. 2 illustrates an example aircraft landing system of the aircraft ofFIG. 1.

FIG. 3 illustrates an example wheel assembly of the aircraft landingsystem of FIG. 2.

FIG. 4 illustrates a tire inflation valve disposed on the example wheelassembly of FIG. 3.

FIG. 5 is a cross-sectional view of the example tire inflation valve ofFIG. 4.

FIG. 6 is a block diagram of an example fuse plug monitoring system.

FIG. 7 is a block diagram of a temperature monitoring unit of theexample fuse plug monitoring system of FIG. 6.

FIGS. 8-9 are a flow diagram of an example method disclosed herein.

FIG. 10 is a block diagram of an example processing platform capable ofexecuting machine readable instructions to implement the exampletemperature monitoring unit of FIG. 7.

Wherever possible, the same reference numbers will be used throughoutthe drawing(s) and accompanying written description to refer to the sameor like parts. As used in this disclosure, stating that any part (e.g.,a layer, film, area, or plate) is in any way positioned on (e.g.,positioned on, located on, disposed on, or formed on, etc.) anotherpart, means that the referenced part is either in contact with the otherpart, or that the referenced part is above the other part with one ormore intermediate part(s) located therebetween. Stating that any part isin contact with another part means that there is no intermediate partbetween the two parts.

DESCRIPTION

Methods and apparatus to monitor components of an aircraft landingsystem are disclosed herein. During a braking event of an aircraft suchas, for example, landing, taxiing, parking, etc., heat is generated bybrakes (e.g., rotors and stators) of a brake assembly. Heat istransferred from the brake assembly to a wheel operatively coupled tothe brake assembly. The wheel may include a fuse plug, which includes aseal that melts at a threshold temperature. If the seal melts, air isreleased from a tire on the wheel. After one braking event or aplurality of braking events in a given period of time, a temperature ofthe fuse plug may increase toward the threshold temperature. The examplemethods and apparatus disclosed herein may be used to monitor atemperature of the wheel and/or a temperature of the fuse plug to enablean operator of the aircraft, an aircraft control system, etc. todetermine when to schedule future braking events (e.g., landing at adestination) or perform one or more actions to cool the brake assemblyand/or the wheel to prevent the fuse plug from melting.

Heat from the brake assembly may be transferred to the fuse plug duringthe braking event (e.g., as the brakes are applied during landing) andafter the braking event (e.g., once the aircraft is parked). Thus, atemperature of the fuse plug may continue to increase following thebraking event. In some examples, a fuse plug monitoring system includesa temperature monitoring unit in communication with a first temperaturesensor disposed on the wheel and a second temperature sensor disposed onthe brake assembly. In some examples, the temperature monitoring unitestimates a temperature of the fuse plug at a future time based on aninitial temperature of the wheel and/or the fuse plug and a temperatureof the brake assembly.

The temperature monitoring unit may determine the initial temperature ofthe fuse plug at a first time via the first temperature sensor. Based onthe temperature of the brake assembly determined via the secondtemperature sensor at or near the first time, the temperature monitoringunit determines a brake energy associated with the brake assembly. Overa period of time (e.g., 30 minutes), the brake energy may be transferredto the wheel and/or the fuse plug as heat, thereby increasing atemperature of the fuse plug. In some examples, the temperaturemonitoring unit estimates an increase in the temperature of the fuseplug over the period of time based on the brake energy. Based on theincrease in temperature, the temperature monitoring unit may estimate asubsequent temperature of the fuse plug (e.g., a temperature of thewheel and/or fuse plug at the future time such as, for example, thirtyminutes from the first time).

The temperature monitoring unit may determine a peak temperature of thefuse plug. The peak temperature is a maximum temperature resulting froma braking event. If the temperature of the brake assembly is increasingor decreasing at the first time, the subsequent temperature may not bethe peak temperature. To determine the peak temperature of the fuseplug, the temperature monitoring unit monitors the temperature of thebrake assembly over time and identifies a peak temperature of the brakeassembly at a second time. An initial temperature of the fuse plug at ornear the second time and an amount of the brake energy associated withthe peak temperature of the brake assembly are determined. Based on theinitial temperature of the fuse plug at the second time and the brakeenergy, a subsequent temperature (e.g., a temperature at a future timeafter the second time) of the fuse plug is determined. This subsequenttemperature is the peak temperature of the fuse plug as a result of abraking event. The peak temperature of the fuse plug may be used todetermine if the fuse plug will melt between the second time and thefuture time, if initiating an action to cool the brakes and/or the wheelassembly may prevent the fuse plug from melting, a nearest time at whichthe aircraft may perform another braking event without melting the fuseplug, etc.

FIG. 1 illustrates an example aircraft 100, which may be used toimplement methods and apparatus to monitor components of an aircraftlanding system are disclosed herein. In the illustrated example, theaircraft 100 includes a landing system 102 to support the aircraft 100on a surface 104 (e.g., a runway) and enable the aircraft 100 to taxi,take off, land, etc. The example landing system 102 includes a frontlanding gear unit 106 and two rear landing gear units 108 and 110.However, the above-noted numbers of front and rear landing units aremerely examples and, thus, other examples may employ other numbers offront landing gear units and/or rear landing gear units withoutdeparting from the scope of this disclosure.

To travel from one destination (e.g., airport) to another, the exampleaircraft 100 may perform a plurality of braking events such as, forexample, taxiing from a departure gate to a runway, landing, taxiingfrom a runway to an arrival gate, and parking. During a given timeperiod (e.g., one day), the example aircraft 100 may travel or bescheduled to travel to a plurality of destinations and, thus, perform orbe scheduled to perform a plurality of braking events.

FIG. 2 illustrates an example landing gear unit 200, which may be usedto implement the landing system 102 of the example aircraft 100 ofFIG. 1. In the illustrated example, the landing gear unit 200 includes astrut 202, an axle assembly 204, two wheel assemblies 206 and 208, andtwo brake assemblies 210 and 212. Each of the brake assemblies 210 and212 is coupled to the axle assembly 204 and a respective one of thewheel assemblies 206 and 208. The example landing gear unit 200 mayinclude a plurality of actuators, sensors and/or other devices, whichmay be controlled by and/or communicate with one or more aircraftcontrol systems of the example aircraft 100.

The wheel assemblies 206 and 208 of the example landing gear unit 200are substantially similar, and the brake assemblies 210 and 212 of theexample landing gear unit 200 are substantially similar. Thus, thefollowing description of the brake assembly 210 and the wheel assembly206 disposed on a right side of the strut 202 in the orientation of FIG.2 is applicable to the brake assembly 212 and the wheel assembly 208disposed on a left side of the strut 202 in the orientation of FIG. 2.Therefore, to avoid redundancy, the wheel assembly 208 and the brakeassembly 212 on the left side of the strut 202 in the orientation ofFIG. 2 are not separately described.

In the illustrated example, wheel assembly 206 includes a wheel 214 anda tire 216. The example brake assembly 210 includes a housing 218,brakes (e.g., one or more rotors and stators), pistons and/or othercomponents. In the illustrated example, the brakes are received in atubewell 220 of the wheel 214. When the brake assembly 210 is operated,the brakes convert kinetic energy of the wheel 214 into brake energy(e.g., heat energy). As a result, a temperature of the brake assembly210 increases. In the illustrated example, a brake temperature sensor222 (e.g., a thermocouple) is coupled to the landing gear unit 200 toacquire information related to the temperature of the brake assembly 210(“brake temperature information”). The example brake temperature sensor222 of FIG. 2 is disposed on the housing 218 of the brake assembly 210.In other examples, the brake temperature sensor 222 may be coupled toother components of the brake assembly 210, the axle assembly 204, thestrut 202, the wheel 214, and/or any other suitable component of thelanding gear unit 200. As described in greater detail below, thetemperature of the brake assembly 210 may be used to estimate an amountof brake energy that may be absorbed by the wheel 214 and/or a fuse plug300 (FIG. 3) disposed on the wheel 214 as a result of a braking event.

FIG. 3 is a perspective view of a first side of the example wheelassembly 206 of FIG. 2. In the illustrated example, the wheel 214includes the fuse plug 300. The example fuse plug 300 is coupled to thewheel 214 via the tubewell 220. Although one fuse plug is shown in theillustrated example, the wheel 214 may include a plurality of fuseplugs, which may be spaced apart along the wheel 214 (e.g., three fuseplugs radially spaced apart by about 120 degrees).

The example fuse plug 300 of FIG. 3 is in communication with theinterior space of the tire 216 between the wheel 214 and the tire 216.When a temperature of the fuse plug 300 is below a thresholdtemperature, the fuse plug 300 enables the tire 216 to be inflatedand/or pressurized. If the temperature of the fuse plug 300 reaches orexceeds the threshold temperature, a portion (e.g., a eutectic core) ofthe fuse plug 300 melts to release air from in the tire 216.

The example wheel assembly 206 includes a heat shield 302 coupled to thewheel 214. The example heat shield 302 is disposed between the brakeassembly 210 and the wheel 214 to prevent and/or mitigate convectiveand/or radiative heat transfer from the brake assembly 210 to the wheel214 and the fuse plug 300.

FIG. 4 is a perspective view of a second side of the example wheelassembly 206 of FIGS. 2-3. In the illustrated example, the wheelassembly 206 includes a cap 400 coupled to the wheel 214. The wheelassembly 206 also includes a tire inflation valve 402. Air may be flowedinto the tire 216 via the tire inflation valve 402 to inflate the tire216 and/or pressurize the tire 216.

FIG. 5 is a cross-sectional view of the example wheel 214 and theexample tire inflation valve 402 of FIG. 4. In the illustrated example,a wheel temperature sensor 500 (e.g., a thermocouple) is disposed in thetire inflation valve 402. In other examples, the wheel temperaturesensor 500 is disposed in and/or on other portions of the wheel assembly206 (e.g., the cap 400, the tubewell 220 of the wheel 214, a rim of thewheel 214, etc.). The wheel temperature sensor 500 acquires informationrelated to a temperature of the wheel 214 (“wheel temperatureinformation”). As described in greater detail below, the temperature ofthe wheel 214 and the temperature of the brake assembly 210 may be usedto estimate a peak temperature of the fuse plug 300 as a result of abraking event.

In the illustrated example, a position sensor 502 (e.g., anaccelerometer) is coupled to the tire inflation valve 402. The positionsensor 502 may be used to determine and/or monitor a rotational positionof the tire inflation valve 402 and, thus, the wheel temperature sensor500. In the illustrated example, the position sensor 502 is coupled tothe tire inflation valve 402 via thermal insulation 504.

FIG. 6 is a block diagram of an example fuse plug monitoring system 600disclosed herein. The example fuse plug monitoring system 600 includes atemperature monitoring unit 602 in communication with the braketemperature sensor 222, the wheel temperature sensor 500 and theposition sensor 502 of FIGS. 2-5. The example temperature monitoringunit 602 determines peak temperatures of the wheel 214 and/or the fuseplug 300 resulting from one or more braking events performed by theexample aircraft 100. The temperature monitoring unit 602 may beimplemented by and/or in communication with an aircraft control system604 disposed on the aircraft 100 or a monitoring device 606 disposedoutside of the aircraft 100 (e.g., a portable or handheld device (e.g.,a laptop, a smartphone, a portable diagnostic tool, etc.), a workstation(e.g., located in a maintenance facility, a ground control facility,etc.), and/or any other suitable device and/or system. The exampletemperature monitoring unit 602 may operate while the aircraft 100 is onthe surface 104 of Earth and/or in flight.

During operation of example aircraft 100, the wheel temperature sensor500 communicates the wheel temperature information to the temperaturemonitoring unit 602. The example position sensor 502 communicates theposition information to the temperature monitoring unit 602. In theillustrated example, based on the position information, the temperaturemonitoring unit 602 determines a rotational position of the fuse plug300 relative to the rotational position of the wheel temperature sensor500. Because heat Q generally rises, if the fuse plug 300 is disposedabove the wheel temperature sensor 500 relative to the surface 104 ofEarth, a temperature of the fuse plug 300 may be greater than atemperature of the wheel 214 determined via the wheel temperature sensor500. If the fuse plug 300 is disposed below the wheel temperature sensor500 relative to the surface 104 of Earth, the temperature of the fuseplug 300 may be less than the temperature of the wheel 214 determinedvia the wheel temperature sensor 500. In some examples, the fuse plug300 is assumed to be at a highest point on the wheel 214 relative to thesurface 104 of Earth. Thus, based on the wheel temperature informationand the position information, the temperature monitoring unit 602determines an initial temperature of the fuse plug 300. The initialtemperature is a temperature at a first time.

During a braking event, kinetic energy is converted into brake energyvia the brake assembly 210. As a result, heat Q is generated by thebrake assembly 210. The heat Q may be transferred from the brakeassembly 210 to the axle assembly 204, the heat shield 302, the wheel214, the fuse plug 300, and/or other components of the landing gear unit200. As a result, a temperature of the wheel 214 and/or a temperature ofthe fuse plug 300 may increase during the braking event. After thebraking event has concluded (e.g., upon takeoff, once the aircraft 100is parked, etc.), the wheel 214 and the fuse plug 300 may continue toabsorb heat energy generated by the brake assembly 210. As a result, thetemperatures of the wheel 214 and the fuse plug 300 may increase until agiven amount of time after the braking event has concluded.

The example brake temperature sensor 222 communicates brake temperatureinformation to the temperature monitoring unit 602. Based on the braketemperature information, the temperature monitoring unit 602 determinesa temperature of the brake assembly 210. Based on the temperature of thebrake assembly 210, the temperature monitoring unit 602 estimates anamount of brake energy to be transferred from the brake assembly 210 tothe wheel 214 and/or the fuse plug 300. In some examples, thetemperature monitoring unit 602 further determines an estimatedtemperature increase of the wheel 214 and/or the fuse plug 300 over apredetermined amount of time (e.g., thirty minutes) based on the brakeenergy. Based on the initial temperature of the wheel 214 and/or thefuse plug 300 and the estimated temperature increase, the temperaturemonitoring unit 602 estimates a subsequent temperature of the wheel 214and/or fuse plug 300. The subsequent temperature is a temperature at afuture time subsequent to the first time.

In some examples, the temperature monitoring unit 602 determines if thesubsequent temperature of the wheel 214 and/or the fuse plug 300 is apeak temperature of the wheel 214 and/or the fuse plug 300. The peaktemperature is a maximum temperature resulting from a braking event. Thepeak temperature of the wheel 214 and/or the fuse plug 300 is determinedbased on a peak temperature of the brake assembly 210 as a result of thebraking event. For example, if the temperature of the brake assembly 210is increasing or decreasing at the first time, the temperaturemonitoring unit 602 may determine that the subsequent temperature(determined based on the initial temperature at the first time) is notthe peak temperature of the wheel 214 and/or the fuse plug 300. Once thebrake assembly 210 reaches the peak temperature at a second time, amaximum amount of brake energy to be transferred to the wheel 214 and/orthe fuse plug 300 as a result of the braking event is determined basedon the peak temperature of the brake assembly 210. Using the initialtemperature of the wheel 214 and/or the fuse plug 300 at the second timeand the maximum amount of the brake energy, the peak temperature of thewheel 214 and/or the fuse plug 300 is determined.

Based on the subsequent temperature, the temperature monitoring unit 602may generate and/or communicate a message. In some examples, the messagemay indicate that the temperature of the fuse plug 300 has or willexceed the threshold temperature. In some examples, the message includesthe initial temperature of the fuse plug 300, the subsequent temperatureof the fuse plug 300, an amount of time until the fuse plug 300 reachesthe subsequent temperature, an indication that the subsequenttemperature is the peak temperature, one or more recommended actions(e.g., in-flight gear extension, in-flight gear retraction, forced brakecooling, initiate brake cooling schedule, etc.). The recommended actionmay be based on the initial and/or the subsequent temperature of thefuse plug 300, and/or other information. In some examples, the messageis displayed via a cockpit display 608, a display 610 of the monitoringdevice 606, and/or any other suitable display.

FIG. 7 is a block diagram of the example temperature monitoring unit 602of FIG. 6. The example temperature monitoring unit 602 includes a brakeenergy estimator 700, an initial temperature determiner 702, a positiondeterminer 704, a subsequent temperature estimator 706, a peaktemperature estimator 708, a clock 710 and a temperature managementprocessor 712.

The example initial temperature determiner 702 receives wheeltemperature information from the wheel temperature sensor 500. Based onthe wheel temperature information, the example initial temperaturedeterminer 702 determines an initial temperature of the wheel 214 and/orthe fuse plug 300. In some examples, the initial temperature of the fuseplug 300 is a function of the initial temperature of the wheel 214. Forexample, the initial temperature of the fuse plug may be determinedusing the following equation:

T _(FP initial) =C ₁ ·T _(W)  Equation 1:

In Equation 1, T_(FP initial) is the initial temperature of the fuseplug 300, T_(W) is the initial temperature of the wheel 214, and C₁ is acorrelation coefficient. In some examples, C₁ is determinedexperimentally. The initial temperature is a temperature of the fuseplug 300 at a first time such as, for example, during a braking event,at a conclusion of the braking event, after the braking event, and/orany other suitable time.

In some examples, the initial temperature determiner 702 determines theinitial temperature of the fuse plug 300 based on a rotational positionof the wheel temperature sensor 500 relative to a rotational position ofthe fuse plug 300. More specifically, the example position determiner704 of FIG. 7 determines a rotational position of the wheel temperaturesensor 500 based on position information received via the positionsensor 502. In some examples, to determine the rotational position ofthe wheel temperature sensor 500 relative to the rotational position ofthe fuse plug 300, the rotational position of the fuse plug 300 isassumed to be at a highest point on the wheel 214 relative to thesurface 104 of Earth. If the fuse plug 300 is disposed above the wheeltemperature sensor 500 relative to the surface 104 of Earth, the initialtemperature determiner 702 may determine that the initial temperature ofthe fuse plug 300 is greater than the temperature of the wheel 214 by anamount that is a function of a difference between the rotationalposition of the fuse plug 300 and the rotational position of the wheeltemperature sensor 500. In some examples, a relationship between theinitial temperature of the fuse plug 300, the temperature of the wheel214, and the difference between the rotational position of the fuse plug300 and the rotational position of the wheel temperature sensor 500 isdetermined experimentally.

The example brake energy estimator 700 receives brake temperatureinformation from the brake temperature sensor 222. Based on the braketemperature information, the example brake energy estimator 700estimates a temperature of the brake assembly 210. In some examples, thebrake energy estimator 700 receives the initial temperature of the wheel214 and/or the fuse plug 300 from the initial temperature determiner702. Based on the temperature of the brake assembly 210 and the initialtemperature of the wheel 214 and/or the fuse plug 300, the brake energyestimator 700 determines an amount of brake energy (e.g., heat) thatwill be transferred to the wheel 214 and/or the fuse plug 300 from thebrake assembly 210. In some examples, the amount of brake energy is afunction of the temperature of the wheel 214 and a state of wear of thebrakes. For example, the brake energy may be determined using thefollowing equation:

BE=T _(W) ·F _(BWS) ·F _(TE).  Equation 2:

In Equation 2, BE is the brake energy, T_(W) is the temperature of thewheel 214, F_(BWS) is a brake wear state correlation factor, and F_(TE)is a correlation factor between the temperature of the brake assembly210 and the brake energy. In some examples, the brake wear statecorrelation factor, F_(BWS), is a constant corresponding to the state ofwear of the brakes (e.g., new, 50% worn, fully worn, etc.). In someexamples, the state of wear of the brakes is assumed to be a fully wornstate. The correlation factor between the temperature of the brakeassembly 210 and the brake energy, F_(TE), may be determined empirically(e.g., based on experimentally determined data) or theoretically (e.g.,by calculating the correlation factor using a mathematical formula basedon a material of a heat sink corresponding to the brake assembly 210 anda mass of the heat sink).

The example subsequent temperature estimator 706 of FIG. 7 estimates asubsequent temperature of the wheel 214 and/or the fuse plug 300. Thesubsequent temperature is a temperature at a future time after the firsttime such as, for example, thirty minutes after the first time. In theillustrated example, the subsequent temperature estimator 706 estimatesan increase in temperature of the wheel 214 and/or the fuse plug 300from the first time to the future time based on the brake energy to betransferred to the wheel 214 and/or the fuse plug 300. Based on theinitial temperature and the estimated increase in temperature, thesubsequent temperature estimator 706 estimates the subsequenttemperature of the wheel 214 and/or the fuse plug 300 (e.g., by summingthe estimated increase in temperature and the initial temperature). Forexample, the subsequent temperature of the fuse plug 300 may bedetermined using on the following Equation:

T _(FP, subsequent) =ΔT _(FP) +T _(FP initial), where ΔT _(FP)=(F_(BE,ΔFP) ·BE).  Equation 3:

In Equation 3, T_(FP, subsequent) is the subsequent temperature of thefuse plug 300; ΔT_(FP) is the estimated increase in temperature of thefuse plug 300; T_(FP initial) is the initial temperature of the fuseplug 300; F_(BE,ΔFP) is a correlation factor between the brake energyand the estimated increase in temperature of the fuse plug 300; and BEis the brake energy. In some examples, F_(BE,ΔFP) is a function of theinitial fuse plug temperature, and F_(BE,ΔFP) may be determinedexperimentally.

The example peak temperature estimator 708 of FIG. 7 determines if thesubsequent temperature is a peak temperature of the wheel 214 and/or thefuse plug 300. In the illustrated example, the peak temperatureestimator 708 monitors the brake temperature information acquired viathe brake temperature sensor 222 to determine if the brake temperatureis increasing, decreasing or substantially constant at the first time.In some examples, the clock 710 provides timing information to theexample peak temperature estimator 708 to enable the peak temperatureestimator 708 to determine a rate of change of the brake temperature.

If the brake temperature is increasing at the first time (e.g., during abraking event), the peak temperature estimator 708 determines that thesubsequent temperature is below the peak fuse plug temperature. If thebrake temperature is decreasing at the first time (e.g., while theaircraft 100 is in flight), the subsequent temperature estimator 706determines that the subsequent temperature is below the peaktemperature. If the brake temperature is substantially constant at thefirst time, the peak temperature estimator 708 determines that thatsubsequent temperature is the peak temperature.

In some examples, the peak temperature estimator 708 determines the peaktemperature of the wheel 214 and/or the fuse plug 300 based on a peakbrake temperature resulting from a braking event. The peak temperatureestimator 708 may determine the peak brake temperature by identifying ahighest brake temperature prior to the brake temperature decreasing. Insome examples, the peak temperature estimator 708 determines the peakbrake temperature by determining the brake temperature when the rate ofchange of the brake temperature is substantially zero (e.g., the braketemperature is constant).

The example temperature monitoring unit 602 of FIG. 7 includes atemperature management processor 712, which receives information fromthe clock 710, the initial temperature determiner 702, the subsequenttemperature estimator 706, and the peak temperature estimator 708. Inthe illustrated example, the temperature management processor 712determines if the subsequent temperature is at or above a thresholdtemperature. For example, the temperature management processor 712 maydetermine if the subsequent temperature of the fuse plug 300 is within apredetermined temperature of the melting point of the fuse plug 300.

In some examples, the temperature management processor 712 generatesand/or communicates one or more messages to the aircraft control system604 and/or the monitoring device 606. In some examples, if thesubsequent temperature is at or above the threshold temperature, thetemperature management processor 712 may generate and/or communicate amessage indicating that the fuse plug temperature has exceeded or willexceed the threshold temperature in a given amount of time. In someexamples, the message includes the initial temperature of the fuse plug300, the subsequent temperature of the fuse plug 300, an amount of timeuntil the fuse plug 300 reaches the threshold temperature and/or thesubsequent temperature, an indication that the subsequent temperature isthe peak temperature, one or more recommended actions (e.g., in-flightgear extension, in-flight gear retraction, forced brake cooling,initiate brake cooling schedule, etc.), and/or other information.

While an example manner of implementing the temperature monitoring unit602 of FIG. 6 has been illustrated in FIG. 7, one or more of theelements, processes and/or devices illustrated in FIG. 7 may becombined, divided, re-arranged, omitted, eliminated and/or implementedin any other way. Further, the brake energy estimator 700, the initialtemperature determiner 702, the position determiner 704, the subsequenttemperature estimator 706, the peak temperature estimator 708, the clock710 and the temperature management processor 712 and/or, more generally,the temperature monitoring unit 602 of FIG. 7 may be implemented byhardware, software, firmware and/or any combination of hardware,software and/or firmware. Thus, for example, any of the brake energyestimator 700, the initial temperature determiner 702, the positiondeterminer 704, the subsequent temperature estimator 706, the peaktemperature estimator 708, the clock 710 and the temperature managementprocessor 712 and/or, more generally, the temperature monitoring unit602 of FIG. 7 could be implemented by one or more circuit(s),programmable processor(s), application specific integrated circuit(s)(ASIC(s)), programmable logic device(s) (PLD(s)) and/or fieldprogrammable logic device(s) (FPLD(s)), etc. When any of the apparatusor system claims of this patent are read to cover a purely softwareand/or firmware implementation, at least one of the brake energyestimator 700, the initial temperature determiner 702, the positiondeterminer 704, the subsequent temperature estimator 706, the peaktemperature estimator 708, the clock 710 and the temperature managementprocessor 712 and/or, more generally, the temperature monitoring unit602 of FIG. 7 are hereby expressly defined to include a tangiblecomputer readable medium such as a memory, DVD, CD, Blu-ray, etc.storing the software and/or firmware. Further still, the exampletemperature monitoring unit 602 of FIG. 7 may include one or moreelements, processes and/or devices in addition to, or instead of, thoseillustrated in FIG. 7, and/or may include more than one of any or all ofthe illustrated elements, processes and devices.

FIGS. 8-9 depict an example flowchart representative of a method orprocess that may be implemented using, for example, computer readableinstructions. The example method of FIGS. 8-9 may be performed using aprocessor, a controller (e.g., the example aircraft control system 604of FIGS. 6-7) and/or any other suitable processing device. For example,the example method of FIGS. 8-9 may be implemented using codedinstructions (e.g., computer readable instructions) stored on a tangiblecomputer readable medium such as a flash memory, a read-only memory(ROM), and/or a random-access memory (RAM). As used herein, the termtangible computer readable medium is expressly defined to include anytype of computer readable storage and to exclude propagating signals.Additionally or alternatively, the example method of FIGS. 8-9 may beimplemented using coded instructions (e.g., computer readableinstructions) stored on a non-transitory computer readable medium suchas a flash memory, a read-only memory (ROM), a random-access memory(RAM), a cache, or any other storage media in which information isstored for any duration (e.g., for extended time periods, permanently,brief instances, for temporarily buffering, and/or for caching of theinformation). As used herein, the term non-transitory computer readablemedium is expressly defined to include any type of computer readablemedium and to exclude propagating signals.

Alternatively, some or all of the example method of FIGS. 8-9 may beimplemented using any combination(s) of application specific integratedcircuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)), fieldprogrammable logic device(s) (FPLD(s)), discrete logic, hardware,firmware, etc. Also, one or more operations depicted in FIGS. 8-9 may beimplemented manually or as any combination(s) of any of the foregoingtechniques, for example, any combination of firmware, software, discretelogic and/or hardware.

Further, although the example method of FIGS. 8-9 is described withreference to the flow diagrams of FIG. 8-9, respectively, otherimplementations of the method of FIGS. 8-9 may be employed. For example,the order of execution of the blocks may be changed, and/or some of theblocks described may be changed, eliminated, sub-divided, or combined.Additionally, one or more of the operations depicted in FIGS. 8-9 may beperformed sequentially and/or in parallel by, for example, separateprocessing threads, processors, devices, discrete logic, circuits, etc.

FIGS. 8-9 illustrate a flowchart representative of an example method 800that can be performed to monitor components of an aircraft landingsystem. The example method 800 may be implemented using the exampletemperature monitoring unit 602 of FIGS. 6 and 7. The example method maybe initiated at predetermined intervals of time, substantiallycontinuously, or in response to a detected event and/or a conditionbeing met (e.g., touchdown from flight, conclusion of a braking event,operation of the brake assembly 210, a manual input, etc.). The examplemethod 800 may be performed while the aircraft 100 is supported on thesurface 104 of Earth (e.g., parked, taxiing, etc.) and/or in flight.

The example method 800 of FIGS. 8-9 begins by determining a temperatureof the wheel 214 of the aircraft 100 via a first temperature sensor(e.g., the wheel temperature sensor 500 of FIG. 5) at a first time(block 802). For example, the initial temperature determiner 702 maydetermine the temperature of the wheel 214 based on the wheeltemperature information received via the wheel temperature sensor 500disposed in the tire inflation valve 402. In some examples, the firsttemperature sensor may be disposed in and/or on the tubewell 220, thecap 400, and/or any other suitable portion of the wheel 214 and/or thewheel assembly 206. The position determiner 704 determines a rotationalposition of the first temperature sensor (block 804). In some examples,the position determiner 704 determines the rotational position of thefirst temperature sensor relative to a rotational position of the fuseplug 300. Based on the temperature of the wheel 214 and the rotationalposition of the first temperature sensor, the initial temperaturedeterminer 702 determines an initial temperature of the fuse plug 300disposed on the wheel 214 (block 806). In some examples, the initialtemperature determiner 702 may determine that the initial temperature ofthe fuse plug 300 is greater than the temperature of the wheel 214 ifthe fuse plug 300 is disposed above the first temperature sensorrelative to the surface 104 of Earth. A difference between thetemperature of the wheel 214 and the initial temperature of the fuseplug 300 is a function of the rotational position of the firsttemperature sensor relative to the rotational position of the fuse plug300.

At or near the first time, a temperature of the brake assembly 210operatively coupled to the wheel 214 is determined via a secondtemperature sensor (e.g., the brake temperature sensor 222 of FIG. 2)(block 808). For example, the brake energy estimator 700 of the exampletemperature monitoring unit 602 of FIG. 7 may determine the temperatureof the brake assembly 210 based on brake temperature informationreceived via the brake temperature sensor 222 disposed on the housing218 of the brake assembly 210. In other examples, the second temperaturesensor may be disposed on the landing gear unit 200 near the brakeassembly 210 (e.g., on the axle assembly 204, strut 202, etc.) and/or onother components of the brake assembly 210. Based on the temperature ofthe brake assembly 210, the brake energy estimator 700 estimates anamount of brake energy to be transferred from the brake assembly 210 tothe fuse plug 300 (block 810).

Turning to FIG. 9, the subsequent temperature estimator 706 determinesan estimated increase in the temperature of the fuse plug 300 over apredetermined amount of time based on the brake energy (block 900). Thesubsequent temperature estimator 706 determines a subsequent temperatureof the fuse plug 300 based on the initial temperature of the fuse plug300 and the estimated increase in temperature of the fuse plug 300(block 902). In the illustrated example, the subsequent temperature is atemperature at a future time after the first time (e.g., thepredetermined amount of time after the first time).

The temperature management processor 712 determines if the subsequenttemperature is at or above a threshold temperature (block 904). Forexample, the temperature management processor 712 may determine if thesubsequent temperature is at or above a temperature at which the fuseplug 300 melts. If the fuse plug 300 is at or above the thresholdtemperature, the temperature management processor 712 generates a firstmessage (block 906). For example, the temperature management processor712 may generate a message including the subsequent temperature, awarning, a recommended action, etc. In some examples, the temperaturemanagement processor 712 selects the recommended action (e.g., from atable or database) based on the subsequent temperature. For example, ifthe subsequent temperature is at or near the temperature at which thefuse plug 300 melts, the temperature management processor 712 may selecta recommended action such as, for example, initiation of a brake coolingschedule (e.g., in which the aircraft 100 is to be parked for apredetermined amount of time).

If the subsequent temperature is below the threshold temperature, thepeak temperature estimator 708 determines if the subsequent temperatureis a peak temperature of the fuse plug 300 (block 908). In someexamples, the peak temperature estimator 708 determines if thesubsequent temperature is the peak temperature based on a rate of changeof the brake assembly temperature at or near the first time. Forexample, if the brake assembly temperature is increasing at the firsttime, the peak temperature estimator 708 determines that the subsequenttemperature is less than the peak temperature and, thus, is not the peaktemperature. In some examples, if the brake assembly temperature isidentified as a maximum temperature of the brake assembly 210 prior to adecrease in the brake assembly temperature, the subsequent temperatureis determined to be the peak temperature. If the subsequent temperatureis not the peak temperature, the temperature management processor 712generates a second message (block 910). The second message may includethe brake temperature, the initial fuse plug temperature, the subsequentfuse plug temperature, an indication that the fuse plug temperature isnot the peak temperature, a recommended action (e.g., initiate brakecooling schedule, proceed to a destination, etc.), and/or any otherinformation. If the subsequent temperature is a peak temperature of thefuse plug 300, the temperature management processor 712 generates athird message (block 912). The third message may include any informationrelated to the fuse plug 300, a recommended action (e.g., initiate brakecooling schedule, proceed to a destination, etc.) and/or any otherinformation. The first message, the second message and/or the thirdmessage may be communicated to the aircraft control system 604, themonitoring device 606, and/or any other suitable system and/or device.In the illustrated example, once the first message, the second messageor the third message is generated, communicated and/or displayed, theexample method returns to block 802.

FIG. 10 is a block diagram of an example processing platform 1000capable of executing machine readable instructions to implement thetemperature monitoring unit 602 of FIGS. 6-7. The processing platform1000 can be, for example, a server, a computer, a mobile device (e.g., alaptop, a smart phone, etc.), an Internet appliance, the aircraftcontrol system 604, the monitoring device 606, or any other type ofcomputing device.

The system 1000 of the instant example includes a processor 1012. Forexample, the processor 1012 can be implemented by one or moremicroprocessors or controllers from any desired family or manufacturer.

The processor 1012 includes a local memory 1013 (e.g., a cache) and isin communication with a main memory including a volatile memory 1014 anda non-volatile memory 1016 via a bus 1018. The volatile memory 1014 maybe implemented by Synchronous Dynamic Random Access Memory (SDRAM),Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory(RDRAM) and/or any other type of random access memory device. Thenon-volatile memory 1016 may be implemented by flash memory and/or anyother desired type of memory device. Access to the main memory 1014,1016 is controlled by a memory controller.

The processing platform 1000 also includes an interface circuit 1020.The interface circuit 1020 may be implemented by any type of interfacestandard, such as an Ethernet interface, a universal serial bus (USB),and/or a PCI express interface.

One or more input devices 1022 are connected to the interface circuit1020. The input device(s) 1022 permit a user to enter data and commandsinto the processor 1012. The input device(s) can be implemented by, forexample, a keyboard, a mouse, a touchscreen, a track-pad, a trackball,isopoint and/or a voice recognition system, a switch, a button, anaircraft cockpit console device, etc.

One or more output devices 1024 are also connected to the interfacecircuit 1020. The output devices 1024 can be implemented, for example,by display devices (e.g., a liquid crystal display, a cathode ray tubedisplay (CRT), a printer and/or speakers). The interface circuit 1020,thus, typically includes a graphics driver card.

The interface circuit 1020 also includes a communication device (e.g.,communication device 56) such as a modem or network interface card tofacilitate exchange of data with external computers via a network 1026(e.g., an Ethernet connection, a digital subscriber line (DSL), atelephone line, coaxial cable, a cellular telephone system, a satellitecommunications system, etc.).

The processing platform 1000 also includes one or more mass storagedevices 1028 for storing software and data. Examples of such massstorage devices 1028 include floppy disk drives, hard drive disks,compact disk drives and digital versatile disk (DVD) drives. The massstorage device 1028 may implement the local storage device 62.

The coded instructions 1032 that, when executed, cause a machine toperform the example method 800 of FIGS. 8-9 may be stored in the massstorage device 1028, in the volatile memory 1014, in the non-volatilememory 1016, and/or on a removable storage medium such as a CD or DVD.

Although certain example methods, apparatus and articles of manufacturehave been described herein, the scope of coverage of this disclosure isnot limited thereto. On the contrary, this disclosure covers allmethods, apparatus and articles of manufacture fairly falling within thescope of the claims.

The Abstract at the end of this disclosure is provided to comply with 37C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature ofthe technical disclosure. It is submitted with the understanding that itwill not be used to interpret or limit the scope or meaning of theclaims.

1. An apparatus comprising: a temperature monitoring unit to becommunicatively coupled to a first temperature sensor of at least one ofa wheel or a fuse plug coupled to the wheel, and a second temperaturesensor of a brake assembly operatively coupled to the wheel, thetemperature monitoring unit including: an initial temperature determinerto determine an initial temperature of at least one of the wheel or thefuse plug based on a temperature value to be provided by the firsttemperature sensor; a brake energy estimator to estimate a temperatureof the brake assembly based on a temperature value provided by thesecond temperature sensor; a subsequent temperature estimator toestimate a subsequent temperature of at least one of the wheel or thefuse plug, the subsequent temperature to be determined after thedetermination of the initial temperature; and a peak temperatureestimator to determine if the subsequent temperature is a peaktemperature of the at least one of the wheel or the fuse plug.
 2. Theapparatus of claim 1, further including a temperature managementprocessor to determine if the subsequent temperature is equal to orgreater than a threshold temperature.
 3. The apparatus of claim 2,wherein the temperature management processor to generate a messageindicating that the fuse plug temperature at least one of has exceededor will exceed the threshold temperature in a given amount of time whenthe subsequent temperature is at or above the threshold temperature. 4.The apparatus of claim 1, further including a position determiner todetermine a position of the first temperature sensor relative to arotational position of the fuse plug.
 5. The apparatus of claim 4,further including a position sensor to receive a positional value of thewheel, the position determiner to receive the positional value from theposition sensor to determine the rotational position of the fuse plug.6. The apparatus of claim 1, wherein the initial temperature is atemperature of the fuse plug at a first time during at least one ofduring a braking event, at a conclusion of the braking event, or afterthe braking event.
 7. The apparatus of claim 1, wherein the brake energyestimator determines an amount of brake energy to be transferred to atleast one of the wheel or the fuse plug from the brake assembly based onthe temperature of the brake assembly and the initial temperature of atleast one of the wheel or the fuse plug.
 8. A method comprising:determining an initial temperature of at least one of a wheel or a fuseplug based on a temperature value to be provided by a first temperaturesensor; estimating a temperature of a brake assembly based on atemperature value provided by a second temperature sensor; afterdetermining the initial temperature, estimating a subsequent temperatureof the at least one of the wheel or the fuse plug; and determining ifthe subsequent temperature is a peak temperature.
 9. The method of claim8, further including determining if the subsequent temperature is equalto or greater than a threshold temperature.
 10. The method of claim 9,further the temperature management processor to generate a messageindicating that the fuse plug temperature at least one of has exceededor will exceed the threshold temperature in a given amount of time whenthe subsequent temperature is at or above the threshold temperature. 11.The method of claim 8, further including determining a position of thefirst temperature sensor relative to a rotational position of the fuseplug.
 12. The method of claim 11, further including receiving apositional value of the wheel.
 13. The method of claim 12, furtherincluding determining the rotational position of the fuse plug based onthe received positional value of the wheel.
 14. The method of claim 8,wherein the initial temperature is a temperature of the fuse plug at afirst time during at least one of during a braking event, at aconclusion of the braking event, or after the braking event.
 15. Atangible computer-readable medium comprising instructions that, whenexecuted, cause a machine to: determine, via an initial temperaturedeterminer, an initial temperature of at least one of a wheel or a fuseplug based on a temperature value to be provided by a first temperaturesensor; estimate, via a brake energy estimator, a temperature of a brakeassembly based on a temperature value provided by a second temperaturesensor; after determining the initial temperature estimate, via asubsequent temperature estimator, a subsequent temperature of the atleast one of the wheel or the fuse plug; and determine, via a peaktemperature determiner, if the subsequent temperature is a peaktemperature.
 16. The computer-readable medium as defined in claim 15comprising instructions that, when executed, cause the machine todetermine if the subsequent temperature is equal to or greater than athreshold temperature.
 17. The computer-readable medium as defined inclaim 15 comprising instructions that, when executed, cause the machineto to generate a message indicating that the fuse plug temperature atleast one of has exceeded or will exceed the threshold temperature in agiven amount of time when the subsequent temperature is at or above thethreshold temperature.
 18. The computer-readable medium as defined inclaim 17 comprising instructions that, when executed, cause the machineto determine a position of the first temperature sensor relative to arotational position of the fuse plug.
 19. The computer-readable mediumas defined in claim 18 comprising instructions that, when executed,cause the machine to receive a positional value of the wheel.
 20. Thecomputer-readable medium as defined in claim 19 comprising instructionsthat, when executed, cause the machine to determine the rotationalposition of the fuse plug based on the received positional value of thewheel.